Hertel 74129289 Straight-flute Drill Bit 21/64 in Carbide

Product Description

The HERTEL 74129289 is a solid carbide straight-flute drill bit designed for precision drilling in hard and difficult-to-machine materials. Built to material grade C2 carbide, it delivers the rigidity and edge retention needed when working with stainless steel, nickel alloys, titanium alloys, chrome alloy steels, and heat-treated alloy steels. The 21/64 inch (0.3281 inch decimal) diameter and 140-degree notched point geometry promote accurate entry and reduce thrust force on tough workpiece materials. A web-thinned construction further lowers cutting resistance at the chisel edge. This bit ships bright and uncoated, ready for direct use or application-specific coating by the end user.

This drill bit is suited for machining, fabrication, and maintenance applications where ferrous and high-strength alloy workpieces are common. Typical use cases include aerospace component drilling, precision metalworking shops, industrial maintenance, and MRO operations. The straight-flute design is well-matched for short-chipping materials where chip evacuation through a helical flute is not required. Right-hand cutting direction is standard for conventional drill press and CNC spindle use.

Key Features

• Solid carbide C2 material grade provides superior hardness and wear resistance in alloy and stainless steel drilling
• 140-degree notched point angle reduces walking and improves self-centering on entry
• Web-thinned construction lowers thrust requirements and reduces heat at the cutting edge
• Straight-flute geometry suited for short-chipping materials including stainless steel and nickel alloys
• Diameter tolerance held to +0.0000 to -0.0005 inches for close-tolerance hole requirements
• Bright/uncoated finish allows immediate use or application of a secondary coating

Compatibility

Designed as a straight-flute carbide drill bit for use in conventional drill presses, CNC machining centers, and manual or CNC lathes where right-hand cutting and straight-flute geometry are specified for hard or short-chipping metallic workpieces.

Installation Notes

Install and operate this bit in a rigid, properly trammed spindle to minimize runout, which is critical when holding tight diameter tolerances. Secure workpieces firmly before drilling to prevent walking or chatter on entry, especially with the notched point geometry. Coolant-through capability is not supported on this bit, so external coolant or cutting fluid application is recommended when drilling deep holes or hard alloy materials. This bit should be handled and stored carefully to protect the carbide cutting edges from chipping caused by contact with other tooling.